1. Field of the Invention
The present invention relates to a system and method for determining physical properties of harvested agricultural products on harvesting equipment such as a combine.
2. Description of the Background Art
The conventional method of analyzing agricultural products harvested by a combine involves allowing the agricultural product to fall from the end of the combine elevator into a chute and collecting the agricultural product in a test chamber where load cells determine the weight of the sample, a moisture sensor senses the moisture in the sample, and a sonar device positioned above the chamber determines the volume of the sample. Some of the disadvantages of this approach are that the flow of agricultural product must be interrupted in order to perform an analysis and that it is not possible to determine the other constituents, e.g., protein or oil, of the sample.
Another method of analyzing agricultural products on a combine, exemplified by U.S. Pat. Nos. 5,751,421 and 5,991,025, involves positioning a lamp in the chute or test chamber to irradiate the agricultural product with near-infrared light as it falls from the elevator. Light reflected from the falling product is collected by a sensor and transmitted through a fiber optic bundle to a defraction grating that spreads the reflected light over a photodiode array. By analyzing the strength of the radiation at each photodiode, the amount of constituents in the product sample can be determined. While this approach enhances conventional methods by permitting constituents of a product sample to be measured in a relatively short time period, it is still necessary for the flow of product to be interrupted when the test chamber is full so that other conventional measurements can be made.
There remains a need in the art for an improved method of analyzing agricultural products on harvesting equipment such as a combine.
Accordingly, it is an object of the present invention to provide a method and apparatus for analyzing agricultural products on harvesting equipment such as a combine that overcomes the disadvantages of the prior art.
A first aspect of the present invention is generally characterized in a system for analyzing agricultural products on harvesting equipment, such as a combine, that creates a flow of harvested agricultural product. The system includes a test chamber and a near infrared spectrometer disposed within a housing capable of being mounted on the harvesting equipment. The test chamber has a first open end adapted to receive a small sample from the flow of harvested agricultural product and a second open end adapted to expel the sample from the test chamber. First and second doors are disposed on opposite sides of the test chamber to control the flow of product into and out of the test chamber. The spectrometer preferably includes a source of near infrared radiation disposed in the housing adjacent the test chamber so as to emit near infrared radiation into the test chamber, and a near infrared detector disposed in the housing adjacent the test chamber so as to receive near infrared radiation exiting the test chamber. The system preferably also includes vibration damping elements that attenuate vehicle vibrations to a level allowing the spectrometer to operate while agricultural product is harvested. The system optionally includes one or more of a computer that operates the first and second doors to control the flow of harvested agricultural product into and out of the test chamber, a fill sensor that indicates when the test chamber is full, at least one temperature probe disposed within the test chamber, a device for maintaining the temperature in the test section within a predetermined range, means for automatically inserting a standard sample into the test chamber at predetermined intervals, and means for adjusting a gap width of the test chamber to accommodate different types of agricultural products.
Another aspect of the present invention is generally characterized in a method of analyzing agricultural products on harvesting equipment, such as a combine, that creates a flow of harvested agricultural product. The method includes the steps of selectively diverting a portion of the harvested agricultural product from the flow created by the harvesting equipment without stopping the flow of product, collecting the diverted portion of the agricultural product in a test section disposed on the harvesting equipment, and analyzing the diverted portion of the agricultural product in the test section using near infrared spectrometry. The analysis is preferably conducted using near infrared transmittance with the sample held stationary within a test chamber disposed in the test section. The method optionally includes one or more of the steps of controlling the flow of product into and out of the test chamber by operating doors disposed on opposite sides of the test chamber, automatically calibrating the spectrometer with a standard sample or no sample in the test chamber at predetermined intervals, mounting the near infrared spectrometer on vibration damping elements to isolate the spectrometer from vibration of the harvesting equipment so that operation of the equipment can continue uninterrupted during the analysis, determining the location where the diverted portion of the agricultural product was harvested using a global positioning system, maintaining the temperature of the near infrared spectrometer within a predetermined range, and controlling a gap width of the test chamber to accommodate different types of agricultural products.
The above and other features and advantages of the present invention will be further understood from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.